Tracking prod seasons in a sales curve against comparators

I am trying to replicate a report we put together in Excel weekly that tracks a running sum of single ticket sales by production season against 3 different groupings - average sales, low (turtles) and high (ponies). All of the data for the comparators was pulled out of T-Stats and we pull the weekly data for performances within the next 8 weeks out of T-Stats, too. We then hand enter that info into excel and convert that pivot table into a line chart. Here is a screen shot of the pivot table and line chart from Excel:

It would be wonderful if I could put together a widget in Analytics to track upcoming performances in this same way but I am getting stuck because I can't figure out how to create custom groupings of performances to track ponies, average and turtles separately (and averages isn't technically the average, I toss out a few outliers) nor how to track against each upcoming production season separately. In the line chart in Analytics you can only break by one unique item. Though you can filter that item I can choose one production season or a grouping of production seasons but not several groupings of production seasons. 

Even in pivot table form, if you filter prod seasons anywhere it affects that measure everywhere, it isn't possible to add two instances of prod season in columns for example and filter them separately. 

We are RMA users and sales curves are easy enough to use there to track individual production seasons but even in RMA you can track against one forecast (average for example) but not several forecasts to split the 3 comparator lines. 

Is there some work around I'm missing here? 

Thanks,

Amy